(1) Field of the Invention
The field of the invention is in the broad sense medical syringes. More specifically, the invention relates to dilatation catheters of the inversion-eversion type and an actuator therefor characterized by the use of a compressible fluid to maintain nearly constant pressure on an incompressible fluid which fills the catheter while the balloon element of the catheter is everted and inflated.
(2) Description of the Prior Art
We are not aware of any device which uses a compressible fluid in order to maintain pressure on the incompressible fluid that fills the catheter.
A Double Lumen Dilatation Catheter having a catheter portion of the type incorporated in the present invention is shown in Chin, et al. U.S. Pat. No. 4,526,175. An alternative method of inflating a catheter balloon by means of a Combined Large and Small Bore Syringe is shown in Chin, U.S. Pat. No. 4,476,866.